There's a new research paper out that will probably set the blogosphere ablaze in coming days, especially the fake skeptic part of it. Why? Because it espouses a theory that explains the slowdown in the rate of temperature rise of the past decade and a half (depending on your starting point).
According to the paper by Cowtan and Way, called Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends, the slowdown is actually smaller, but it's not apparent because temperatures aren't recorded properly in a couple of areas around the globe, the most important being, of course, the Arctic.
This doesn't really come as a surprise, as we have seen the massive temperature spikes since 2007, especially during freeze-up when the Arctic Ocean releases all the heat accumulated during the melting season to be able to freeze up. Apparently there are a lot differences in the way these temperatures are measured or inferred by the various global temperature data sets.
You can read more about this in a blog post by Stefan Rahmstorf on RealClimate (where I took the graph on the upper right from), but I'd also like to draw attention to a blog post from last April that also looks at some discrepancies between the GISS LOTI and NCEP/NCAR data sets (Cowtan and Way focus on HadCRUT4). The analysis is done by - who else - Chris Reynolds on his Dosbat blog. Here's an excerpt and a graph:
As with the previous post on Arctic Amplification it is apparent that summer warming is negligible, this is due to energy going into melting ice, not raising temperatures. However the latent heat of energy melting ice, and ocean warming, is released in September to November, with later warming possibly due to thinner ice and ice growth.
These temperature anomalies will only be picked up by a handful of meteorological stations on islands in the Arctic, therefore will not be being strongly represented in GISS LOTI. It seems to me that rather than concluding that NCEP/NCAR is wrongly showing warming of a pattern shown by other reanalysis datasets, and backed up by mechanistic understanding of the changes in sea ice, it is more likely that GISS LOTI is missing a significant element of warming that could be as large as an extra 0.5degC in the annual average.
Read all of it here.
So it could be that the 'hiatus' in global temperature rise really isn't one. What will happen when the Sun becomes more active again, ENSO isn't dominated by La Niña, China and India start filtering aerosols out of their emissions? The prospect worries me, to be frank, as I don't think temperatures in the Arctic will drop any time soon, despite the cold summer we just witnessed.
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UPDATE
Here's a very nice graph produced by Jos Hagelaars from the Our Changing Climate blog that shows that the slowdown (or 'hiatus' or 'pause') in global atmospheric temperature increase hasn't disappeared, it has just become smaller because of Cowtan and Way's inclusion of the Arctic and other data-less regions (update: due to a calculation error the graph has been updated):
The fact that the upward trend isn't going up as fast in the period since the 70's still probably has to do with ENSO being dominated by La Niñas, an inactive Sun, Asian aerosols, etc. There's a good chance that even if all these things don't flip back and keep dampening atmospheric temps, the rate of temperature increase will gradually go back to what it was. And the Arctic will probably continue to get warmer much faster than the rest of the globe.
Commenter Dominik Lenné also has an interesting back-of-the-spreadsheet analysis on his blog showing how some of the 'missing' heat (I don't miss it at all) might have gone into melting Arctic sea ice. Rob Dekker, get over there and have a look (if you have the time): Global Warming 'hiatus': it might be the ice
The skeptic blogosphere is already spinning up loud and voluminous ad hominem attacks on the authors, and unsupported criticism of their methods.
Nice to have some analysis that explains the discrepancy in some reporting, and What we already have seen (i.e. spiking polar temps)
Posted by: jdallen_wa | November 14, 2013 at 20:23
The authors are appealing for enough cash to make this paper open access, via SkS, here...
http://www.skepticalscience.com/news.php?n=2283
Posted by: idunno | November 14, 2013 at 20:29
It's off to a slow start but the story might gain more traction.
The Guardian,
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2013/nov/13/global-warming-underestimated-by-half
Science Daily,
http://www.sciencedaily.com/releases/2013/11/131113092217.htm
Posted by: L. Hamilton | November 14, 2013 at 20:46
"set the blogosphere ablaze in coming days"
This kind of research will always heat things up, it will never cool things down, if you catch my drift. ;-)
Posted by: Hans Verbeek | November 14, 2013 at 22:58
Yes, Hans, it's called AGW. :-P
Posted by: Neven | November 14, 2013 at 23:06
Neven--Thanks for putting 'hiatus' in scare quotes. There never has been much of a hiatus.
Only by cherry picking a starting date characterized by an extremely warm El Nino and by cherry picking a period thereafter that is far too short to exhibit anything but climate static can one come to the conclusion/delusion that there was any kind of hiatus.
Just picking average global temps for each decade over the last fifty years makes this overpoweringly clear: the globe is on a steadily warming trajectory.
Posted by: wili | November 14, 2013 at 23:23
A little article out of the Northwest Territories supporting the topic at hand-
“Oil and gas waste is leaking into four lakes in the Northwest Territories, according to a new study.
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The waste piles, which are called sumps, were left behind decades ago during oil and gas exploration in the Mackenzie Valley.
“
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The sumps were frozen into the permafrost, and today more than 200 of them dot the region. A recent study tested more than 100 lakes. 20 of which were near sumps. Researchers found four of these lakes had elevated levels of salts, particularly chloride, an important component of drilling waste fluids.
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Ed Hoeve, an engineering consultant, says when the man-made sumps were created, they were seen as a permanent and frozen solution. But permafrost in the Mackenzie Valley is two degrees warmer than it was when the waste was frozen into the tundra.
http://www.cbc.ca/news/canada/north/oil-and-gas-waste-leaking-into-n-w-t-lakes-study-shows-1.2418767
Posted by: Colorado Bob | November 15, 2013 at 01:25
Hello,
from somewhere i got the idea to connect the atmospheric warming "hiatus" to the heat necessary to melt the 8000 km³ of perennial ice lost during the last 20 years or so.
The calculations can be found here: http://remarksandobservations.wordpress.com/2013/11/15/global-warming-hiatus-it-might-be-the-ice/
What do You think of that?
Posted by: dominik lenné | November 15, 2013 at 04:13
Dominik
I like your calculations, they show good imagination and perseverance. Others may have considered this but your numbers are simple and understandable from common sense. Sometimes this is missed by complex systems.
The Way paper is fraught with complexity and extrapolations but fills a big gap in our present understanding.
Posted by: r w Langford | November 15, 2013 at 05:13
The oceans are responsible for 93% of the heat capacity of the biosphere. In the last decade sea levels have risen by 3.2 ± 0.4 cm and in the decade before that? 3.2 ± 0.4 cm - the same, within the level of uncertainty. Where did the water come from? Data from the Gravity Recovery and Climate Experiment (GRACE) show that about 1.0 cm of the 3.2 cm in the past ten years came from melting of Greenland (~2600 Gt) and Antarctic (~800 Gt) land ice. The best estimates indicate that ~7 mm out of the 6.4 cm in the past twenty years came from groundwater depletion. The rest came from THERMAL EXPANSION. The freakin' oceans are literally acting as a liquid expansion thermometer, like a mercury thermometer or red-dyed alcohol thermometer. The heat content of the oceans - again, 93% of the biosphere's heat capacity - is unquestionably continuing to rise. Just as fast in the last ten years as in the 10 years before. Sea level has been rising for more than 100 years, but faster in the past twenty years. Continued global warming is as much a stone fact as it is a fact that the rising level of a liquid thermometer indicates the heating of the liquid in the thermometer.
Posted by: Tim | November 15, 2013 at 07:34
You have the right of it, Tim... The oceans, and by extension sea ice are the 250 KG gorilla of AGW. That is where the energy has gone, and is where relatively modest changes in temperature translate into staggering changes in our climate.
Atmospheric temperature changes while spectacular, are still a side show.
Posted by: jdallen_wa | November 15, 2013 at 08:44
@Dominik That seems like a very interesting point. In my opinion it would be clearer if you, or anybody could superimpose the icemelt energy figures on the temperature graph.
OT, but the current ocean acidification story doing the rounds has some startling stuff about the Arctic:
http://www.bbc.co.uk/news/science-environment-24904143
"The effect of acidity is currently being felt most profoundly felt in the Arctic and Antarctic oceans. These chilly waters hold more CO2 and increasing levels of the gas are turning them acidic more rapidly than the rest of the world.
The more acidic they become, the more damaging they are to the shells and skeletons of marine organisms.
The researchers say that by 2020, ten percent of the Arctic will be inhospitable to species that build their shells from calcium carbonate. By 2100 the entire Arctic will be a hostile environment."
Posted by: idunno | November 15, 2013 at 10:53
On topic, hotwhopper catalogues the response from Curry and Watts here...
http://blog.hotwhopper.com/2013/11/anthony-watts-protest-about-cowtan-way.html
Posted by: idunno | November 15, 2013 at 13:09
"it is more likely that GISS LOTI is missing a significant element of warming that could be as large as an extra 0.5degC in the annual average."
Does that mean that total warming since preindustrial times is really 8.5 degrees C so far rather than just 8?
Posted by: wili | November 15, 2013 at 20:10
And just as the ocean functions as a thermometer it also serves as a battery, a vast storehouse with a nearly unlimited capacity to absorb energy. Deep ocean temperature increases will be with us for thousands of years.
Posted by: Shared Humanity | November 15, 2013 at 20:53
Dominik, Jim Hansen included some calculations in this paper on the contribution of ice melting on the earth's energy imbalance. He worked it out to about 0.2 watts/m of globe per year, or about 10% of net forcing. It may be worth comparing your numbers with his. http://www.columbia.edu/~jeh1/mailings/2011/20110826_EnergyImbalancePaper.pdf
Posted by: Josh | November 15, 2013 at 23:25
Me also almost was thinking to thank Neven for the scare quotes. But then it occured to me as somehow insulting. Thanking Neven for being seriously professional and stating the obvious in sufficient detail (scare quotes suffice). Well, now with that paper it is muuuuuuuch easier to see the obvious. Still even now this ugly embodiment of human silliness is floating around the Internets: "hiatus" typed without scare quotes!.
Actually, the whole situation is/was exceedingly insulting. All those serious people, some scientists even, talking hiatus - without ever caring to eyeball the f*n data. (I already had enough of that 2 years back with Vahrenholt's nonsense campaign. Yes, methinks such active innumeracy is a deeply worrisome psychopathic feature in the discourse of that omphaloskeptic ostrich, Homo S "Sapiens".)
For all those who said hiatus I propose the following punishment:
Get a big sheet of paper and make a dunce's hat for yourself. Write "hiatus" on it. Then click the standard evidence, the updated (or not) Fig. 1A in Hansen et al. (2006). Print that out 10, 50, or 100 times (depending on your scientific eminence). Now, get a pencil and a transparent ruler. Turn each print at random (this will optimize your statistics), find 1970 and find and draw a straight trend line. (Try to not get distracted by that red 5y average line: Thinking about it may risk your mental health.) With each sheet have a moment of silent meditation, fathoming the fluctuations. Then measure the trend line slopes and use e.g. Excel to calculate their mean and standard deviation. Compare with recent scientific literature.
Posted by: Martin Gisser | November 16, 2013 at 01:11
The PIOMAS graph has been updated to include October.
Posted by: D_C_S | November 16, 2013 at 02:03
PIOMAS update:
Latest value: 2013-10-31 8.218
I have updated my graphics at ArctischePinguin for the latest data.
Monthly Data
Daily Anomalies
Daily data
Daily data with a "prediction" based on exponential trend
Posted by: Wipneus | November 16, 2013 at 07:46
Pretty intense low pressure either side of Svarlsbard, very high AMO.
Posted by: idunno | November 16, 2013 at 09:25
I think Cowtan & Way's analysis seems pretty solid and pretty convincing, but it doesn't mean there was not a "pause" of some fashion in the growth in tropospheric temperatures (really, the increase in tropospheric energy). If this seems contradictory...read on.
First, for those who don't know me-- I on the "warmist" side of things. I think it is highly likely that human activity (chiefly the burning of fossil fuels) has been altering Earth's energy balance for many decades. More net energy is being added to Earth's system than is leaving each year specifically because the the massive transfer of carbon from the lithosphere to the atmosphere through the burning of fossil fuels. I also think that there is a real potential for this "human carbon volcano" as I call it, to have some sort of catastrophic consequences for life on Earth, including humans, if we don't collectively figure out how to turn off this human carbon volcano.
Having made my position clear, I do want to explain how Cowtan & Way could have produced some excellent, solid, and valid research, and the "pause" still be real in some fashion. The operative words here are "in some fashion", as what we really care about, when you actually look at the details of what the human carbon volcano is doing, it is an energy balance issue and not a sensible heat in the troposphere issue. Measuring troposphere sensible heat (the metric for the "pause") is only one way of measuring energy in the troposphere, and as such, sensible heat is actually a proxy for energy in the troposphere. Moreover, the measurement of changes in sensible heat in the troposphere has become an even more broadly used proxy (by some less knowledgeable people) for changes of energy in the entire Earth system. We know the use of sensible heat as a proxy for changes in energy in the entire Earth energy system is absolutely wrong for many reasons, but not the least of which is the fact that the changes in the heat content of the oceans vastly dwarf energy in the atmosphere by many orders of magnitude, and the very best data we have tells us that there absolutely was no pause in the increase in energy in the oceans over the past 10, 20, 30 and even 40+ years. On average, the oceans down to about 2000m have been adding somewhere around 0.5 x 10^22 Joules of energy every year for the past 40+ years.
We also know that during the past decade or slightly more, there have been 3 major things that have caused a slowdown in the increase in tropospheric sensible heat. They are: 1) a slowdown in the net flow of energy from ocean to atmosphere. Mind you, globally, the net flow of energy from ocean to atmosphere is always very positive, so much so that over 50% of the energy in the atmosphere at any given time has come directly from the ocean in one form or another. But during the last 10 or so years, a cool PDO has slightly decreased this rate of flow. 2) There has been a moderate increase in natural aerosols from a moderate uptick in global volcanic activity. This has been measured directly in the stratospheric optical depth and translates into slightly less solar SW hitting the ground. 3) The sun has been hitting some of the lowest activity levels in at least a century and this has also translated into slightly less energy across many wavelengths reaching Earth. These three things combined have caused a "pause" in the growth of tropospheric sensible heat (excluding the Arctic). What Cowtan & Way have shown is that very likely, if we include the Arctic, this pause is not nearly as great as it might appear, which can be due to the unequal warming of the Arctic from the rising greenhouse gas forcing. But what Cowtan & Way did not measure in their extrapolation (or kriging) efforts was an even more important metric of moist enthalpy. Moist enthalpy of course is a different measurement of tropospheric energy, that takes into account the amount of moisture in the atmosphere at a given temperature, and in fact is a more accurate measurement of energy. Given that the Arctic will typically have much lower moist enthalpy measurements, we must realize that the results of Cowtan & Way actually put too much emphasis on the Arctic in terms of the actual energy content being measured, even if their kriging duplicates temperatures exactly as they occurred in the Arctic. Essentially, the further you go toward the equator, as humidity levels increase, identical temperatures represent more net energy in the atmosphere. Thus, Cowtan & Way might very well be correct (as far as sensible heat goes), but it can also be true (as I highly suspect it is) that the tropospheric "pause" is a real phenomenon in terms of a slowdown in the growth of net energy in the troposphere (for the 3 reasons I've stated). Ultimately though, from a more broad perspective, as long as the human carbon volcano keeps erupting so strongly, we can expect the net energy content of the Earth climate system to continue on the upward climb, and the best overall measurement of this remains the unstoppable growth in ocean heat content.
Posted by: R. Gates | November 16, 2013 at 20:42
I've added a graph by Jos Hagelaars to the post that visualizes the difference between HadCRUT4 and Cowtan+Way's calculations, in relation to the CMIP5 RCP8.5 scenario from AR5.
Posted by: Neven | November 16, 2013 at 21:48
Oh, and a link to Dominik's interesting blog post. Thanks, Dominik.
Posted by: Neven | November 16, 2013 at 21:54
Regarding the notion that some of the "pause" in tropospheric sensible heat rise could be energy that is going into the melting of the ice. I think that's pretty likely, but it still pales in comparision to the net energy that the oceans are retaining. I really like the thought process though-- anything that gets us to a more accurate accounting of the human carbon volcano being an issue of energy balance in the Earth system, with sensible heat in the troposphere being only one measurement (or proxy) of this energy, and certainly sensible heat is transformed, or more crudely "sucked out of" the troposphere for the state change of ice to water. If we really want to understand the actual sensitivity of the climate system to the human carbon volcano and a doubling of CO2 (and methane and N2O) then we need to measure all the ways that energy is being added to the system. Toward this end, the most important thing that is going on right now is the early stages of planning for a big expansion of the Argo float program, adding more floats and sending more of them deeper on a consistent basis then ever before.
Posted by: R. Gates | November 16, 2013 at 22:24
“a big expansion of the Argo float program”…
At what cost? How much more scienctific evidence do governments need before starting to spend what effort is left to ability on actual carbon emission cuts?
Thanks for the explanation on energy enthalpy in the thermodynamic system of Earth’s biosphere, R. Gates. You have well explained what I have felt but couldn’t tell about concentrating on temperatures.
The hard values temperature readings provide are too easy seen as reflecting the actual state of global warming. As often, the process is a lot more complicated than it seems.
And precarious to a comparable level.
Posted by: Werther | November 18, 2013 at 09:11
On Topic! (How did this happen?)
Judith Curry has a handwaving post up related to the C+W paper here:
http://judithcurry.com/2013/11/18/uncertainty-in-arctic-temperatures/
Comment 2 comes from Way.
Posted by: idunno | November 19, 2013 at 11:54
Thanks Idunno,
I guess I should be bothered enough to read the lead post, I'm afraid I got bored. After an evening of number crunching I'm looking for something lighter.
Posted by: Chris Reynolds | November 19, 2013 at 21:32
Hi Chris,
Way's comment is actually a question to Curry; so you can probably quite safely take the rest of the month off.
http://greenfyre.wordpress.com/2011/04/28/are-you-disrespectin-my-family/
Posted by: idunno | November 19, 2013 at 22:28
Hi Idunno,
I wish I could, I intend to have a break between Christmas and New Year, the firm closes over that period and I need a rest, but before then: I'm in the process of breaking PIOMAS gridded data down into the regions used by Cryosphere Today.
Posted by: Chris Reynolds | November 20, 2013 at 20:52
Idunno, I don't know (no pun intended) why we bother reading whatever Judith Curry elaborates, she is hopelessly gone foraging
bad data from contrarian lands. If there is any doubt about Arctic temperatures, the recent open waters at sea ice minima has answered the matter in spades without any expert needed to speak a word. The scant surface statistics reflect this warming.
I rather we read about how satellites determine the temperatures between the stations, this is a basic educational duty someone will have to come up with.
Posted by: wayne | November 21, 2013 at 04:20
Inspired by a recent small jet stream apparently out of place, I demonstrate the changed climatic implications by thinner sea ice. http://eh2r.blogspot.ca/
Posted by: wayne | November 21, 2013 at 06:33
The full C+W paper is now available, if you click on the download pdf link here...
http://onlinelibrary.wiley.com/doi/10.1002/qj.2297/abstract
Posted by: idunno | December 04, 2013 at 17:11
Neven, said :
Sorry it took me so long.
Hansen had previously estimated the heat flux of sea ice volume melted since 1995 to be 0.01 W/m^2.
I posted a detailed comment on his article, which confirms that finding.
It appears that the energy that was needed to melt sea ice over the past 18 years is not significant in the global energy balance.
Thus direct effect of melting sea ice cannot be responsible for any significant planetary temperature change over that period.
The IN-direct effect of melting sea ice (albedo feedback) IS significant (0.13-0.15 W/m^2). But of course, that is a WARMING effect (of the Arctic mainly), and thus opposite from claims 'hiatus' claimed.
Posted by: Rob Dekker | December 07, 2013 at 02:53